1. Field of the Invention
The present invention relates to a method and apparatus for generating a thumbnail of a digital image, and more particularly, to a method and apparatus for generating a thumbnail in a size requested by an application at high definition and high speed to browse a digital image.
2. Description of the Related Art
Recently, digital still camera (DSC) photos with a high resolution of 4 to 8 million pixels have become widespread and equipment such as a personal video recorder (PVR), a home audio/video (AV) center, and a portable multimedia player (PMP) having a large capacity of a storage device can perform a photo album function.
Such equipment has a large storage capacity but has a low central processing unit (CPU) power and thus cannot efficiently process a large-capacity high-definition digital image. Accordingly, to maximize efficiency of the limited CPU power, a thumbnail of the large-capacity high-definition digital image is generated and stored when the large-capacity high-definition digital image is stored in a storage device. During browsing, the thumbnail is displayed but not the original image. In a full-view mode, the original image is displayed.
In the conventional method, the thumbnail has a minimum size needed for browsing and is stored in an RGB format to reduce a decoding time when it is displayed.
In the conventional method, when the original image is used to view a full image regardless of the size of a display apparatus, the large-capacity high-definition original image needs to be decoded even if the entire original image cannot be displayed on a screen of the display apparatus. As a result, image displaying time increases. For example, while an 8 million pixel image has a size of 3400×2300 pixels, a television (TV) usually has a very low resolution of about 960×540 pixels. Accordingly, it is inefficient to decode and display an original image when the 8 million pixel image is reproduced in the TV, because the entire 8 million pixel image cannot be displayed on the TV.
Meanwhile, when images in an application are browsed, various sizes of thumbnails may be needed. When a thumbnail stored in a small size is enlarged to a larger size, picture quality decreases and display speed is slow.
As described above, in the conventional method of generating a thumbnail, it is inefficient and difficult to browse and display a large-capacity high-definition image in a short time with a low CPU power in an application requiring various sizes of thumbnails.